Process and apparatus for the stufferbox crimping of yarns

ABSTRACT

Process and apparatus are disclosed for threading in a yarn crimping device such as a stuffer crimper wherby discharge of yarn from the device is detained during initial threadup an amount of yarn is present in the crimping chamber to effect sufficient crimp.

United States Patent Rietjens Oct. 16, 1973 [5 PROCESS AND APPARATUS FORTHE 2,617,603 11/1952 Griset 57/34.5 x STUFFERBQX CRIMPING 0F YARNS2,704,430 3/1955 Harris 57/34.5 3,526,023 9/1970 Mertensm 28/l.7

Inventor: Pierre L. L. M. RietjensQArnhem,

Netherlands Assignee: Akzona Incorporated, Ashville,

N.C. Filed: July 13, 1971 Appl. No.2 162,066

Foreign Application Priority Data July 14, 1970 Netherlands 7010429 US.Cl. 28/1.7, 28/72.14 Int. Cl. D02g 1/12 Field of Search ..28/1.7, 72.14;57/345 References Cited UNITED STATES PATENTS Griset 57/345 X FOREIGNPATENTS OR APPLICATIONS 257,817 10/1967 Austria 28/1.7

Primary Examiner-Louis K. Rimrodt AttorneyFrancis W. Young [57] ABSTRACTProcess and apparatus are disclosed for threading in a yarn crimpingdevice such as a stuffer crimper wherby discharge of yarn from thedevice is detained during initial threadup an amount of yarn is presentin the crimping chamber to effect sufficient crimp.

6 Claims, 3 Drawing Figures Patented Oct. 16, 1973 3,765,068

INVENTOR.

P. L'.L. M. RIETJENS fww. 7M

ATTORNEY PROCESS AND APPARATUS FOR THE STUFFERBOX CRIMPING OF YARNS Theinvention relates to a process for the stufferbox crimping of yarns,threads, or tows, in which the material to be crimped is forced with theaid of feed means into one or successive, communicating chambers of acrimping apparatus in which during normal operation a wad of crimpedmaterial is formed, and the crimped yarn is discharged at the end of thechamber(s), a signalling device being provided which responds to asupply of crimped material in the chamber(s), and that during thethreading in of the crimping apparatus the crimped material maytemporarily be discharged via a suction device.

The invention also comprises an apparatus for carrying out the aboveprocess.

A process of the type indicated above may be considered known from theBritish Patent Specification No. 1,049,953. During normal operation theyarn is forced against a wad or supply of yarn already crimped. At itsdischarge end the stuffing chamber is partly closed by a hinged flapwhich is loaded by a weight whose magnitude partly determines themagnitude of the stuffing pressure in the stuffing chamber. After theyarn has left the stuffing chamber, it enters a connecting bufferchamber whose discharge opening is partly closed by a lightly loadedflap. The discharge end of the buffer chamber and the flap aresubstantially transparent and on either side of the buffer chamber thereare provided a light source and a light-sensitive pick-up, respectively.This photoelectric measuring device forms part of a control system,"known in itself, for the stufferbox crimping process. This controlsystem so operates that upon detection by the photoelectric pick-up of asufficiently large wad of crimped material, a signal is given forincreasing the rate at which the yarn is discharged from the bufferchamber. As soon as the photoelectric pick-up detects an insufficientamount of crimped material in the buffer chamber, a signal is providedfor reducing the rate at which the yarn is discharged from the ingapparatus and by meansof a suction device very rapidly dischargedtemporarily to a collecting device. As a result of the high dischargerate, the material to be treated is pulled through'the chambers ofthe-crimping apparatus substantially as a straight, uncrimped thread.Since in that case no wad of crimped material is formed in the stuffingchamber, no crimp can be imparted to the yarn, so that onlyuncrimpedyarn is produced during thread'in. In the further threading inthe yarn is passed through the other parts of the machine and finallyarrives at the rotating winding spool in order to form a packagethereon. The threading in process is then completed and the yarnis woundon a spool at a normal speed while forming a package, so that in thestuffing chamber a wad of yarn is formed and after a short time alsoproperly crimped yarn of normal quality is wound.

A disadvantage to this known method of threading in consists in thatpart of the yarn wound on the spool is non-crimped and must be regardedas waste. Use being made of high processing speeds, for instance, of1.000 to 2,000 meters/minute, and each machine having a large number ofprocessing points, the resulting amount of waste is fairly considerable.I

The invention has for its object to provide a process of the typedescribed in the opening paragraphs which does not show theaforementioned drawback. The process according to the invention ischaracterized in that during threading in of the crimping apparatus thesignalling device that normally controls the yarn discharge rate fromthe buffer chamber (as described above) is temporarily coupled to thesuction device. In operation, the suction device is manually operated tothreadin yarn material through the crimping apparatus and then, thedischarge of material via the suction device is stopped until asufficient amount of crimped material is present in the chamber(s). Thismay be done by using, for example, the signal from the photocellsignalling device discussed above. In such an instance, the photocelldevice will sense when there is insufficient yarn material in thecrimping or buffer chamber (depending on the number of in-line chambers)and the signal thus produced will activate a shut-off valve on thesuction device until the photocell senses a sufficient amount of yarnmaterial in the chamber. After sufficient material has accumulated inthe chamber, the suction control shut-off valve will be de-activated,and the suction device will begin drawing a crimped yarn from thechamber. In this manner, an operator may thread-in a crimping chamberand go about his other responsibilities until crimped yarn is beingdrawn from the crimping chamber. Upon returning to the position, theoperator may simply break the yarn going into the suction device andfinish threading the yarn to a windup spool, thereby eliminating theuncrimped waste usually formed on the prior art packages.

A particularly simple process, in which the suction device is actuatedby the vacuum produced .by compressed air, is according to the inventioncharacterized in that the signalling device is so coupled to a supplyvalve for compressed air from the suction device that said valve remainsclosed until a sufficient amount of crimped materia is present in thechamber(s). If the signalling device comprises a photoelectric pick-up,the process according to the invention iswith advantage characterized inthat upon detection of a sufficiently large amount of crimped material,the photoelectric pick-up provides a signal for opening the supply valvefor compressed air. I i

The invention will be explained further with reference to theacompanying schematic drawing.' I

FIG. 1 shows an apparatus for'the spinning, drawing, stufferboxcrimping, and winding of yarns.

FIG. 2 shows an embodiment of a stufferbox crimping apparatus on alarger scale.

FIG. 3 shows a cross-section along the line III-III in FIG. 2.

In FIG. 1 a bundle of freshly spun threads 1 leaves a spinbox 2 and istransported in the direction indicated by the arrow by means of thedriven feed roller 3 with idler roller 4, whichhave a peripheral speedof, for instance, 400 meters/minute. When on the roller 3, the melt-spunpolyamide yarn will have cooled down to a temperature of about 40 C.Subsequently, the yarn is passedto a pair of driven draw rollers 5 and6, which are heated at a temperature in the range of to C. and have aperipheral speed of 1,600 meters/minute,

so that the draw ratio of the yarn is 4:1. In order to avoid slippage,the yarn is wrapped a few times both around the roller 3 and around therollers 5 and 6. The drawn and pre-heated yarn is transported over aguide roller 7 and forced into the stuffing chamber by a pair ofcooperating stuffing wheels 8 and 9 which rotate in opposite directions,the stuffing chamber being provided with a flap 12 which is loaded by aweight 11. After the yarn has left the stuffing chamber 10, it arrivesin a buffer chamber 13 at the end of which there is provided a flap 15which is only loaded by a light spring 14. On one side of the bufferchamber 13 there is positioned a light source 16 and on the other sidethere is a schematically represented photoelectric pickup 17. As isparticularly apparent from FIG. 3, the stufferbox crimper is of the opentype, which implies that the walls of the stuffing chamber and thebuffer chamber are substantially formed by two parallel plates 18 and19. At the level of the light source 16 and the pickup 17, the chamberwalls are transparent, so that the amount of yarn in the buffer chambercan be measured photoelectrically. The winding device 22 serves towithdraw the yarn from the buffer chamber 13 by way of the guide rollersand 21, the yarn being wound on a package 23 by means of a grooved drum24.

The suction device 25 is to be displaced by hand and may be attached tothe machine frame. The suction device 25 substantially comprises asupply line 26 for compressed air, in which line an air valve 27 isprovided for starting and stopping the suction device. The compressedair produces a vacuum in an aspirator type housing 28 and a tube 29, asa result of which the yarn can be sucked into the tube 29. The suckedyarn and the compressed air are discharged through a tube 30 and, via aflexible tube, deposited in a known manner in a collecting vessel forwaste material. Between the photoelectric pick-up 17 and the air valve27 there is provided means 31 for temporarily conveying a signal fromthe photoelectric pick-up device 17 to the air valve 27. The air valve27 may then be controlled by signals from the photoelectric pick-updevice.

During the threading in the tube 29 of the suction device 25 is placedunder the spinbox 2 and emerging threads from the spinbox 2 are suckedinto the suction device by air from a supply 26 passing through airvalve 27 to the aspirator housing 28.

Subsequently, the freshly spun yarn from spinbox 2 is passed, by the useof the tip of tube 29, over the feed roller 3 with idler roller 4 andover the rotating draw rollers 5 and 6, after which the yarn is passedover the guide roller 7 and between the stuffing wheels 8, 9 into thestuffing chamber 10 and the buffer chamber 13. The excess yarn duringthis part of the threading-in is captured by the suction device 25.Immediately after the yarn has passed through the stufferbox crimper,the discharge of yarn via the suction device 25 is stopped until asufficient amount of crimped material is present in the buffer chamber.As soon as the photoelectric pick-up 17 detects a sufficient amount ofcrimped material in the buffer chamber, the pick-up 17 provides via theline 31 a signal for opening the air valve 27, upon which the suctiondevice 25 is re-started. The suction device will then withdraw crimpedyarn from the buffer chamber, which yarn is rapidly threaded in bypassing it over the guide rollers 20 and 21 to the winding device 22.

Within the scope of the invention, various modifications may be made.For instance, instead of a photoelectric signalling device, it ispossible to use a pneumatic, mechanical, or differently operatingsignalling device. Instead of applying stuffing wheels for forcing thematerial to be treated into the stuffing chamber, use may be made of amedium under pressure, for example, steam. Moreover, the processaccording to the invention may be applied by means of widely varyingstufferbox chambers, more particularly also in the case of a stufferboxcrimping apparatus in which a supply of crimped yarn is collected and/ortransported by a rotating wheel or a like transporting member.

What is claimed is:

1. Method for threading a crimping chamber in a continuous yarn process,comprising the steps of:

a. feeding yarn continuously from a yarn supply to a crimping device;

b. threading the yarn through the crimping device;

0. discharging the yarn from the crimping device to a temporary yarnwaste collection system;

d. interrupting the discharge ofthe yarn to the waste collection systemuntilsufficient yarn has accumulated in the crimping device to crimp theyarn; and thereafter e. winding the crimped yarn into a package.

2. Apparatus for threading a crimping chamber in a continuous yarnprocess, comprising:

a. means for continuously feeding yarn to the crimping chamber; 7

b. means for feeding yarn through the crimping chamber;

c. a yarn sensing device responsive to yarn accumulation in the crimpingchamber for controlling the amount of yarn in the crimping chamber;

(1. a suction device downstream of said crimping chamber for temporarilyreceiving yarn during threadup; and

e. connective means between said yarn sensing device and suction devicefor stopping said suction device until sufficient yarn has accumulatedin the crimping chamber.

3. Apparatus for threading a stuffer crimping device in a continuousyarn process comprising feed means for the yarn to be crimped, at leastone crimping chamber, a signalling device responsive to accumulated yarnin the chambers, and a suction device operative by the signal device tostop the discharge of material to the suction device until sufficientmaterial is present in the crimping chambers for crimping.

4. Apparatus for threading a crimping chamber from a continuous yarnsupply, comprising a yarn suction device movable relative to saidcrimping chamber for accepting yarn during the threading of the crimpingchamber and means for automatically interrupting said suction deviceuntil sufficient yarn has accumulated in the crimping chamber to crimpthe yarn.

5. The apparatus of claim 4 wherein the suction device interruptionmeans comprises a sensing device attached to the crimping chamber todetermine yarn accumulation in the crimping chamber and control meansoperative from said sensing device for interrupting said suction deviceuntil sufficient yarn has accumulated in the crimping chamber.

6. The apparatus of claim 5 wherein the sensing device comprisesphotoelectric means within the crimping chamber.

- UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,765O68 I Dated October :16 1973 Invent or(s Pierre L.- L. M. Rietjens- Itis certified that error appears in the ahoveidentified patent and thatsaid Letters Patent are hereby corrected as shown below:

In theyab'stract, line l, aft-er threadup; add ---until-v-- I so' thatthe abstract reads: 1

"Process and apparatus are disclosed for threading in-a yarn crimpingdevice such as -a stuffer crimper whereby discharge of yarn from thedevice is detained during initial threadup until an amount of yarn ispresent in the crimping chamber to effect sufficient'crimp.

Signed and-sealed this 20th day of Au ust iwu.

(SEAL) Attest:

McCOY'M. GIBSON, JR; c. MARSHALL 'DANN Attesting Officer Commissioner ofPatents FORM PO-IOSOHO-GS)

1. Method for threading a crimping chamber in a continuous yarn process,comprising the steps of: a. feeding yarn continuously from a yarn supplyto a crimping device; b. threading the yarn through the crimping device;c. discharging the yarn from the crimping device to a temporary yarnwaste collection system; d. interrupting the discharge of the yarn tothe waste collection system until sufficient yarn has accumulated in thecrimping device to crimp the yarn; and thereafter e. winding the crimpedyarn into a package.
 2. Apparatus for threading a crimping chamber in acontinuous yarn process, comprising: a. means for continuously feedingyarn to the crimping chamber; b. means for feeding yarn through thecrimping chamber; c. a yarn sensing device responsive to yarnaccumulation in the crimping chamber for controlling the amount of yarnin the crimping chamber; d. a suction device downstream of said crimpingchamber for temporarily receiving yarn during threadup; and e.connective means between said yarn sensing device and suction device forstopping said suction device until sufficient yarn has accumulated inthe crimping chamber.
 3. Apparatus for threading a stuffer crimpingdevice in a continuous yarn process comprising feed means for the yarnto be crimped, at least one crimping chamber, a signalling deviceresponsive to accumulated yarn in the chambers, and a suction deviceoperative by the signal device to stop the discharge of material to thesuction device until sufficient material is present in the crimpingchambers for crimping.
 4. Apparatus for threading a crimping chamberfrom a continuous yarn supply, comprising a yarn suction device movablerelative to said crimping chamber for accepting yarn during thethreading of the crimping chamber and means for automaticallyinterrupting said suction device until sufficient yarn has accumulatedin the crimping chamber to crimp the yarn.
 5. The apparatus of claim 4wherein the suction device interruption means comprises a sensing deviceattached to the crimping chamber to determine yarn accumulation in thecrimping chamber and control means operative from said sensing devicefor interrupting said suction device until sufficient yarn hasaccumulated in the crimping chamber.
 6. The apparatus of claim 5 whereinthe sensing device comprises photoelectric means within the crimpingchamber.